An Update From the Zoo's Lion Keepers
March 2008
Changing Hours
We've recently made some changes regarding the time the cats spend on exhibit. Traditionally, the lions (and tigers) have been out by 8:30 a.m. during the summer and by 9:30 in the winter, weather and temperature permitting. We have decided that, for the safety of animal keepers, Zoo visitors, and our animals, two keepers must always be present during large carnivore shifting between indoor and outdoor exhibits. To accommodate this rule, the lions and tigers will be available for public viewing from about 10 a.m. to 4 p.m. year round. We will try to have them out earlier.
Birthdays
Three of our lions have had a birthday over the past four months! Luke turned two in October, Shera turned three in November, and Naba turned four in January. Lusaka’s birthday is unknown due to early life circumstances in a private facility from which she was removed. She is not without a day to celebrate, though—the four-year anniversary of her arrival at the National Zoo was in August 2007. We estimate her birth year to be in 1991, making her about 17 years old.
Weighing In
Luke is now up to 410 pounds and continuing to grow. He may gain up to 140 pounds more before reaching his adult weight! To keep up with his growth, Luke is consuming nine pounds of meat each day. Naba and Shera each maintain about 280 pounds by eating seven pounds of meat each day. Lusaka, who is older and less muscular these days, is healthy and in ideal shape at 235 pounds. We keep her in shape with a low-fat meat. All lions receive bunnies, which we receive frozen once a week and bones twice a week. These items serve as enrichment prey items and also help keep their jaw muscles strong and their teeth healthy.
Some visitors have inquired about the lions' body conditions. We are fortunate to have a nutrition staff to assist us with keeping our animals in the best possible shape. Only about five percent of zoos have such a department. Nutritionists determine target weights individually for each of the lions, and monitor the weights we get each month. Visual exams are scheduled periodically for growing animals, such as Luke, and also when we notice any changes in weight gains and losses, which often occur during seasonal changes. The staff also make a close physical assessment of the lions during routine exams during which the animal is anesthetized. We’re happy to report that all of out lions are in optimal physical shape.
Lusaka’s Exam
Lusaka had a physical and dental exam in February. A doctor from the Animal Dental Clinic in Vienna, Virginia, joined the Zoo’s veterinary staff during the procedure to examine her teeth. During the exam the doctor extracted one of her incisors, which was fractured. Lusaka also has some blood work done and veterinarians took radiographs to look for less obvious signs of illness. When the exam was over, Lusaka was declared to be healthy.
So how do you prepare a large carnivore for such a procedure? Lusaka has been trained to walk into a “squeeze cage” where she can be injected with an anesthetic. She then walks back to a den where she falls asleep. Once veterinarians determine that Lusaka is soundly anesthetized, she is put on a gas anesthetic and transported by vehicle to the veterinary hospital for her exam. When the exam is over, she remains on a gas anesthetic until she has been transported back to her enclosure. After her recent exam, she recovered very well from the anesthesia and was back to her normal self by the next day.
Our Nomads
Visitors often inquire about Luke and Lusaka, who go outside individually. During past months, keepers have been working on introductions between the two. Having lived in adjacent dens over the past year, Luke and Lusaka have formed enough of a bond that we hoped to put them outside together. Though the introductions were generally good, Lusaka appeared content having his attention without sharing her territory and often ignored Luke during their monitored time together. Though Luke showed interest in Lusaka, the lack of interest on her part created a doubt that they would co-exist peacefully outside. They continue to interact with the security of a mesh door between them inside, which seems to appease both.
Looking Toward the Future
It’s not unusual that Luke and Lusaka didn’t hit it off. Lusaka had a hysterectomy and is no longer able to reproduce, and Luke is not yet mature. Male lions usually become mature at the age of three but often do not reproduce before the age of four or five because they must be able to take over a pride from other males. Lucky for Luke he is the only male lion in town. In about a year, he may be ready to meet Naba and Shera through introductions. We would expect these introductions with the younger females to be much more productive. In fact, Nababiep has already shown signs that she has begun to cycle and has shown interest in meeting Luke. We expect to see the same from Shera during the next year.
